Abstract
The role of the teacher in the learning of mathematics is one which continues to be refined.
Evidence continues to mount for the relationship between teachers' content knowledge and
pedagogical content knowledge, and the way they structure their classroom lessons. In this
paper we present data from interviews with four teachers about their teaching of
differentiation and derivative. The analysis shows that there are both similarities and
differences in the pedagogical approaches emphasised, and that these are related to the
teachers' conceptual and representational perspectives.